This invention relates to cable connectors; and more particularly relates to a novel and improved compression-type connector in which a single size connector is capable of accommodating different cable sizes.
A problem which has confronted the cable T.V. industry for years has been to provide a single connector size which can accommodate a plurality of different-sized cables. The standard coaxial cable is made up of a center conductor, insulated layer surrounding the conductor, foil layer, braided layer and outer jacket. This is a typical dual shield cable having a single braided layer which is the outer conductor. Depending upon the specific application and frequencies being transmitted through the cable, it is necessary to modify the thickness of the braided layers, and consequently there are dual-shield, tri-shield and quad-shield cables. In general, the higher the frequency the shorter the wavelength and therefore requires more shielding to prevent leakage. For example, the quad-shield cable has two braided layers separated by a foil layer. Also, the braided layer may vary in thickness and density depending upon the frequencies being handled.
U.S. Pat. Nos. 5,863,220 and 6,089,913 are incorporated by reference herein and disclose coaxial cable connectors that have a crimping ring preassembled onto the connector, and the end of the cable has to be inserted through the single crimping ring and into the inner concentric sleeves on the connector. There are definite size limitations imposed on the diameter of the crimping ring to ensure that it is small enough in diameter to effect the necessary inward contraction on the outer sleeve of the connector to result in a good crimp. This means that the pull-out force necessary to separate the cable from the connector is in excess of 40 psi, and the cable should be contracted enough to assure that there is substantially no leakage or frequency loss between the braided layer(s) and the connector. At the same time, the degree of compression must not be so great as to cause the inner sleeve to collapse or be damaged or otherwise result in an impedance problem in the higher frequency ranges. Especially in larger cables, there is real difficulty in reaching a compromise between the optimum inner diameter of the crimping ring which will permit the cable to be easily inserted into the connector sleeve and the size necessary to effect a good crimp. Since the crimping is most important to assure a good connection, typically the inner diameter of the crimping ring is such that it is very difficult to insert the cable into the connector sleeve. This requires manual dexterity on the part of the installer and, after a day of making connections, can be extremely time-consuming, difficult and very tiring.
Accordingly, for professional and residential installations alike, it is desirable to provide a preassembled crimping ring assembly for a compression-type connector which is conformable for use with a wide range in sizes of coaxial cables either for the purpose of splicing cables together or for connecting one cable end to a terminal and nevertheless be capable of achieving the desired sealed mechanical and electrical connection therebetween
It is an object of this invention to provide for a novel and improved compression-type connector which is employs a single crimping member but nevertheless is capable of connecting different size cables either to a terminal or to another connector in an efficient and reliable manner.
Another object of the present invention is to provide for a novel and improved end connector for coaxial cables with a self-contained crimping ring to achieve the necessary sealed mechanical and electrical connection between the cable and the terminal or to another cable; and wherein the crimping ring assembly is so constructed and arranged as to bring about the necessary inward radial deformation or compression of the connector into crimping engagement with the cable in response to axial advancement of the crimping ring assembly with existing compression tools.
A further object of the present invention is to provide for a novel and improved cable connector with pre-assembled crimping ring which will effect sealed engagement between the connector and cable in a minimum number of steps and simplified manner.
In accordance with the present invention, a connector fitting has been devised for connecting a cable having an electrically conductive member to another electrically conductive member, the fitting comprising a sleeve member of a continuous cylindrical configuration sized for insertion of an end of the cable therein, and a cylindrical crimping member having at least one inner tapered annular surface portion dimensioned to advance over the sleeve member, the inner tapered annular surface portion being disposed in close-fitting engagement with said sleeve member whereupon axial advancement of the crimping member along the sleeve member will impart inward radial deformation to the sleeve member into sealed engagement with an external surface portion of the cable. Preferably, the sleeve member includes an outer rearwardly tapered wall portion substantially complementary to the inner tapered annular surface portion of the crimping member, and releasable locking means are provided between the sleeve member and crimping member for releasably mounting the crimping member in preassembled relation to the sleeve member. In one form of information, the releasable locking means includes a first locking member projecting radially inwardly from the inner tapered annular surface portion of the crimping member and a second locking member projecting radially inwardly from an external wall surface of the sleeve member.
The crimping member is preferably designed with an inner tapered annular surface portion which has a progressively increasing tapered angle rearwardly from the leading end of the crimping member, and the sleeve member has an external wall surface which diverges forwardly away from the entrance end of the sleeve and is substantially complementary to the inner tapered annular surface portion of the crimping member.
The fitting of the present invention is specifically adaptable for use with coaxial TV cables for terminating different size cables depending upon the particular application and frequency being transmitted and, to this end, the inner tapered annular surface portion of the crimping member has a diameter at least as great as the outer diameter of the sleeve in order to be preassembled onto the sleeve and tapers to a second inner diameter less than the outer diameter of the sleeve but greater than the diameters of the cables to be inserted therein.
In a two-stage connector in accordance with the present invention, a-pair of crimping rings are arranged in telescoping relation to one another and to the sleeve, the first crimping ring having an inner tapered annular surface portion adapted to advance over the outer surface of the sleeve member as in the first form of invention described herein,and the second crimping member also having an inner tapered annular surface portion so that when the crimping rings are axially advanced over the outer sleeve will cause inward radial deformation of the sleeve into sealed engagement with an external surface of the cable.
There has been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.